FAIR VALUE MEASUREMENTS - Schedule of financial assets and financial liabilities measured at fair value on a recurring basis (Details) - USD ($) $ in Thousands	Dec. 31, 2022	Dec. 31, 2021
Financial assets and financial liabilities measured at fair value
Fair Value	$ 2,461,393	$ 3,981,251
Equity securities	11,535	13,571
Loans held for sale	1,253	23,875
U.S. Treasury securities
Financial assets and financial liabilities measured at fair value
Fair Value	114,061	165,762
Obligations of U.S. government corporations and agencies
Financial assets and financial liabilities measured at fair value
Fair Value	19,779	38,470
Obligations of states and political subdivisions
Financial assets and financial liabilities measured at fair value
Fair Value	257,512	306,869
Asset-backed securities
Financial assets and financial liabilities measured at fair value
Fair Value	469,875	492,186
Commercial mortgage-backed securities
Financial assets and financial liabilities measured at fair value
Fair Value	108,394	614,998
Residential mortgage-backed securities
Financial assets and financial liabilities measured at fair value
Fair Value	1,243,256	2,069,313
Corporate debt securities
Financial assets and financial liabilities measured at fair value
Fair Value	248,516	293,653
Fair Value, Recurring
Financial assets and financial liabilities measured at fair value
Loans held for sale		23,875
Fair Value, Recurring \| Derivative assets
Financial assets and financial liabilities measured at fair value
Derivative assets	42,612	20,314
Fair Value, Recurring \| Derivative liabilities
Financial assets and financial liabilities measured at fair value
Derivative liabilities	72,462	21,501
Fair Value, Recurring \| U.S. Treasury securities
Financial assets and financial liabilities measured at fair value
Fair Value	114,061	165,762
Fair Value, Recurring \| Obligations of U.S. government corporations and agencies
Financial assets and financial liabilities measured at fair value
Fair Value	19,779	38,470
Fair Value, Recurring \| Obligations of states and political subdivisions
Financial assets and financial liabilities measured at fair value
Fair Value	257,512	306,869
Fair Value, Recurring \| Asset-backed securities
Financial assets and financial liabilities measured at fair value
Fair Value	469,875	492,186
Fair Value, Recurring \| Commercial mortgage-backed securities
Financial assets and financial liabilities measured at fair value
Fair Value	108,394	614,998
Fair Value, Recurring \| Residential mortgage-backed securities
Financial assets and financial liabilities measured at fair value
Fair Value	1,243,256	2,069,313
Fair Value, Recurring \| Corporate debt securities
Financial assets and financial liabilities measured at fair value
Fair Value	248,516	293,653
Fair Value, Recurring \| Equity securities
Financial assets and financial liabilities measured at fair value
Equity securities	11,535	13,571
Fair Value, Recurring \| Level 1 Inputs
Financial assets and financial liabilities measured at fair value
Loans held for sale		0
Fair Value, Recurring \| Level 1 Inputs \| Derivative assets
Financial assets and financial liabilities measured at fair value
Derivative assets	0	0
Fair Value, Recurring \| Level 1 Inputs \| Derivative liabilities
Financial assets and financial liabilities measured at fair value
Derivative liabilities	0	0
Fair Value, Recurring \| Level 1 Inputs \| U.S. Treasury securities
Financial assets and financial liabilities measured at fair value
Fair Value	0	0
Fair Value, Recurring \| Level 1 Inputs \| Obligations of U.S. government corporations and agencies
Financial assets and financial liabilities measured at fair value
Fair Value	0	0
Fair Value, Recurring \| Level 1 Inputs \| Obligations of states and political subdivisions
Financial assets and financial liabilities measured at fair value
Fair Value	0	0
Fair Value, Recurring \| Level 1 Inputs \| Asset-backed securities
Financial assets and financial liabilities measured at fair value
Fair Value	0	0
Fair Value, Recurring \| Level 1 Inputs \| Commercial mortgage-backed securities
Financial assets and financial liabilities measured at fair value
Fair Value	0	0
Fair Value, Recurring \| Level 1 Inputs \| Residential mortgage-backed securities
Financial assets and financial liabilities measured at fair value
Fair Value	0	0
Fair Value, Recurring \| Level 1 Inputs \| Corporate debt securities
Financial assets and financial liabilities measured at fair value
Fair Value	0	0
Fair Value, Recurring \| Level 1 Inputs \| Equity securities
Financial assets and financial liabilities measured at fair value
Equity securities	0	0
Fair Value, Recurring \| Level 2 Inputs
Financial assets and financial liabilities measured at fair value
Loans held for sale		23,875
Fair Value, Recurring \| Level 2 Inputs \| Derivative assets
Financial assets and financial liabilities measured at fair value
Derivative assets	42,607	20,314
Fair Value, Recurring \| Level 2 Inputs \| Derivative liabilities
Financial assets and financial liabilities measured at fair value
Derivative liabilities	72,462	21,501
Fair Value, Recurring \| Level 2 Inputs \| U.S. Treasury securities
Financial assets and financial liabilities measured at fair value
Fair Value	114,061	165,762
Fair Value, Recurring \| Level 2 Inputs \| Obligations of U.S. government corporations and agencies
Financial assets and financial liabilities measured at fair value
Fair Value	19,779	38,470
Fair Value, Recurring \| Level 2 Inputs \| Obligations of states and political subdivisions
Financial assets and financial liabilities measured at fair value
Fair Value	257,512	306,869
Fair Value, Recurring \| Level 2 Inputs \| Asset-backed securities
Financial assets and financial liabilities measured at fair value
Fair Value	469,875	492,186
Fair Value, Recurring \| Level 2 Inputs \| Commercial mortgage-backed securities
Financial assets and financial liabilities measured at fair value
Fair Value	108,394	614,998
Fair Value, Recurring \| Level 2 Inputs \| Residential mortgage-backed securities
Financial assets and financial liabilities measured at fair value
Fair Value	1,243,256	2,069,313
Fair Value, Recurring \| Level 2 Inputs \| Corporate debt securities
Financial assets and financial liabilities measured at fair value
Fair Value	248,516	293,653
Fair Value, Recurring \| Level 2 Inputs \| Equity securities
Financial assets and financial liabilities measured at fair value
Equity securities	11,535	13,571
Fair Value, Recurring \| Level 3 Inputs
Financial assets and financial liabilities measured at fair value
Loans held for sale		0
Fair Value, Recurring \| Level 3 Inputs \| Derivative assets
Financial assets and financial liabilities measured at fair value
Derivative assets	5	0
Fair Value, Recurring \| Level 3 Inputs \| Derivative liabilities
Financial assets and financial liabilities measured at fair value
Derivative liabilities	0	0
Fair Value, Recurring \| Level 3 Inputs \| U.S. Treasury securities
Financial assets and financial liabilities measured at fair value
Fair Value	0	0
Fair Value, Recurring \| Level 3 Inputs \| Obligations of U.S. government corporations and agencies
Financial assets and financial liabilities measured at fair value
Fair Value	0	0
Fair Value, Recurring \| Level 3 Inputs \| Obligations of states and political subdivisions
Financial assets and financial liabilities measured at fair value
Fair Value	0	0
Fair Value, Recurring \| Level 3 Inputs \| Asset-backed securities
Financial assets and financial liabilities measured at fair value
Fair Value	0	0
Fair Value, Recurring \| Level 3 Inputs \| Commercial mortgage-backed securities
Financial assets and financial liabilities measured at fair value
Fair Value	0	0
Fair Value, Recurring \| Level 3 Inputs \| Residential mortgage-backed securities
Financial assets and financial liabilities measured at fair value
Fair Value	0	0
Fair Value, Recurring \| Level 3 Inputs \| Corporate debt securities
Financial assets and financial liabilities measured at fair value
Fair Value	0	0
Fair Value, Recurring \| Level 3 Inputs \| Equity securities
Financial assets and financial liabilities measured at fair value
Equity securities	$ 0	$ 0

Amount excluding accrued interest, of investment in debt security measured at fair value with change in fair value recognized in other comprehensive income (available-for-sale).

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Fair value, after the effects of master netting arrangements, of a financial asset or other contract with one or more underlyings, notional amount or payment provision or both, and the contract can be net settled by means outside the contract or delivery of an asset. Includes assets not subject to a master netting arrangement and not elected to be offset.

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Amount of investment in equity security measured at fair value with change in fair value recognized in net income (FV-NI), classified as current.

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Amount, after valuation allowance, of financing receivable held for sale and not part of disposal group. Excludes loan covered under loss sharing agreement and loan classified as investment in debt security.

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